http://starbaseugc.com/index.php/sto...ideo-tutorial/

In this quick and dirty walkthrough, I show you how to go from a space map to a ground map. I use an exterior ground map, but it works the same with space to interior. You don't have to use a reach marker. If an interior based objective in the story tab follows the kill enemies objective in space, you will be able to transition from space to interior.

I hope that helps.